Polishing wheel



July 9, 1940. Q MQNJAR 2,207,439

POLISHING WHEEL Filed 001',- 24, 1959 ATTORNEYS Patented July 9, 1940 UNITED ST TES- reTENTYoFFicE fazhmss VPOLIISHING WnEEL f Percival. lltionjar, Blasdell; N. I Application October- 24, 1939, SerialNo: 300,964 a -9 Claims. (clasp-190$ This invention relates to 'a rotary polishing wheel for polishing, abrading or'finishingobjects and more particularly tov a wheel of this character which has a body capableof being expanded and contracted within an elastic rim for the purpose of securing a polishing band on the periphery of the rim or releasing the same therefrom. One of the purposes of this invention is to provide a polishing wheel of this character 'hav ing'a plurality of body members which are connected by toggles which are adapted to be moved outwardly for straightening the toggles and cause the rim to grip the inner side of the polishing ll band and to be moved inwardly by folding the toggles and releasing the grip of the rim on the polishing band. A further object of this invention is to provide improved means for mounting the body members m of the polishing wheel on a hub by means;which are of simple, strong and durable construction and which will positively transmit motion from the shaft to the body and eificiently guide the body members relative to the hub upon expanding and contracting the wheel as when mounting a polishing band thereon or removing the latter therefrom when the same has become worn and replacement of the same by a new band'is required.

' In, the accompanying drawing: i

Fig. 1 is a side elevation of a polishing wheel embodying these improvements and showing the wheel in its xpanded condition.

Fig. 2 is a diametrical section of the same, taken on line 22, Fig. 1.

Fig. 3 is a view similar to Fig. 1 but showing the wheel contracted.

Fig. 4 is a fragmentary. circumferential section, taken on line 4-4, Fig. 1.

In the following description similar'characters of reference indicate like parts in the several figures of the drawing.

The numeral H! represents an annular polishing band or endless. sleeve which is adapted to be supported on and rotated by the improved wheel forming the subject of this invention, which'band is preferably of cylindrical form and constructed of paper or similar material having its outer side provided with a coating'of abrasive or polishing material to suit the work to be done, such for example, as sand, emery or silicon-carbide commonly used for polishing or grinding purposes.

The numeral ll represents a rotary driving shaft upon which the polishing band is mounted by this improved wheel. In its gen ral organization this wheel comprises an elastic cushion for the'band, a bodyupon which this support is mountedand which has members capableof being expanded and contracted, means for holding said membersin an expanded position, and a hub which is mounted on said shaft and upon which said, body members are capable of moving radial-f bers are arranged so that their concave sides face each other and their'flanges meet end to end and form a cylindrical outer surface on the exterior of the body which engages the inner cylindrical surface of the cushion rim.

For the purpeseof avoiding gaps between the corresponding opposing ends of the body mem'- bers each end of each body member is provided with a transverse row of circumferentially extending tongues l5; alternating with slots l6 which lnterengage with the complementary'fslots and tongues of the companion end of the other body member. Bythis means the two body members are capable of moving toward and from each other as the wheel is expanded and contracted but the'gaps between the ends of the body members are always bridged by the tongues l5, thereby maintaining apractically continuous cylindrical outer surface on the wheel body for engagement with th inner side of the cushion rim so that the polishing band is supported uniformly throughout its circumference and produces an even polishing efiect on the article which is being treated- Movement of the body members for expanding and contracting the wheel as a whole is efiected by toggle mechanism which is constructed as follows:

The numerals l1, [8 represent two'pairs of toggle links forming a set which extends cir-'- cumferentially across the gap between each pair of opposing ends of the body members, the'outer ends of these links overlappingthe respective ends of these body members and pivoted thereto by pins or rivets I9; and'the inner ends thereof overlapping one another and pivotally conne'ctedby a pin or rivet 2|. Upon moving the inner ends of each set of links radially inward the two pairs of the same are folded and the two body members are drawn together so as to contract or reduce the circumference of the wheel, as shown in Fig. 3, and upon moving the inner ends of the pairs of each set radially outward the same are unfolded, thereby separating the body members and enlarging the circumference of the wheel, as shown in Fig. 1., The maximum separation of the body members occurs when the centers of pin 2| connecting the inner ends of each set and the pins I9. 20 connecting the outer ends of the same with the respective body members are in line.

In order to lock the links of each set in their fully unfolded or operative position, stop means are provided whereby the outward movement of the same is arrested when the same are in line and on a dead center or slightly outward beyond the dead center line, for which purpose each set of links is arranged so close to the inner side of the opposing overlapping end parts of the flanges of the body members that theseparts form a stop 22 which is engaged by the inner ends of the links of the respective set when unfolded. By this means these links are prevented from accidentally folding and thus causing the body members to be retained in their fully separated position, whereby the elastic cushion rim is maintained in an expanded condition and caused to grip the inner side of the polishing band so that the latter is firmly supported when engaging the workpiece which is being polished. I

. Although the outward or unfolding action of the'sets of, toggle links can be effected manually byany suitable tool this is preferably effected automatically by centrifugal force which operates to throw the inner ends of the links of both sets outwardly to the fullest extent into their operative unfolded and locked position during the first partof the rotation of the wheel. It is therefore only necessary, after applying the polishing band to the cushion rim while the wheel is contracted, to rotate the wheel as this automatically expands thelatter together with the cushion rim and causes the polishing band to be gripped ready for use. Contraction of the body can be effected by the use of a tool applied manually to the inner ends of the links of both sets and prying the same inwardly suiiiciently to move the central pins 2| off the dead center relative to the end pins I9, 20, whereby these links can be readily moved into their folded position and cause the body members to come together, thereby permitting the cushion rim to contract due to the-resilient character of the same and release the grip on the polishing band which is now free and easily removable from the rim. By this means a worn. polishing band canbe quickly replaced by a new one and thus facilitate polishing operations.

Various means may be employed for mounting the body members of the wheel on the driving shaft'but thoseshown in the drawing are preferred and constructedas follows y The numeral 24 represents a tube which forms part of the hub of the wheel and which is detachably secured on a reduced neck 25 of the shaft between a shoulder 26 on the shaft engaging: the rear end of this tube and a screw nut 2Ton this neck engaging the front end of the tube,"as shown in Fig. 2. 4

- Onits periphery this tube'is provided with twoparallel plates 28 which are arranged in planes extending at right angles across the axis of the shaft and preferably secured thereto by collars ,to the axis of the wheel.

29 projecting axially outwardly from the central parts of these plates and connected with the periphery of the shaft by welding or otherwise. The extremities of these plates project radially from opposite sides of the shaft and form two pairs of hub wings 30 the members of each pair of which are spaced apart and receive between them the inner part of the web 13 of one of the body members. Each of these bodymembers is guidedon one pair of said hub wings so as to be capable of moving thereon radially relative For this purpose the wings of each pair are provided on opposite sides 'of a radial line extending from the axis of the ,wheel with two pairs of guide slots 3| which are arranged parallel with a radial line of the wheel and the web of-each body member is provided with guide pins each of which extends through the web of the respective body member and a pair of guide slots in the companion hub wing. In the preferred construction each of these guide pins'consists of a central part 32 of relatively large diameter passing through the respective web and reduced necks 33 arranged at opposite ends of this central part and passing through a pair. of the guide slots 3! on the adjacent part of the respective wing. This formation of the guide pins provides shoulders 34 between its central large part andits reduced end necks which engage with theinner sides of the respective wingswhereby binding between the body members andthe wings is prevented and freedom of relative movement of these parts is assured. Separation of the wings from opposite sides of the webs is prevented by providing the outer ends of the guide pins with heads 35 which engage with the outer sides of the wings, as shown fig-;' H

From the foregoing it Will be apparent that this invention provides a polishing wheel which comprises relatively few parts which are of simple construction and capable of being produced at low cost, that the completed wheel is strong and durable, that the, polishingband will be reliably supported and that the change from one polishing band to another can be effected quickly and easily. 7 I

I claim as my invention:

1. A polishingwheel comprising a bodyhaving a-plurality of segments arranged'to form a circular supporting surface on the outer side of the several segments, a hub on which the segments are'movably. mounted for expanding-and contracting the body, an elastic rim mounted onthe supporting surfaces of said segments and adapted to carry an abrasive band, and toggles connecting the' respective opposing ends of the several segments. r v

2. A polishing wheel comprising a body. having a plurality of segments'arranged to form'a cir+ cular supporting surface on the outer side of the several segments, a hub on which the segments are 'movably mounted for expanding and contracting the body, an elastic rim mounted on the supporting surfaces of said segments and adapted to carry an abrasive band, and toggles connecting the respective opposing ends of the several segments and each toggle including links extending circumferentially across the space between adjacent parts of the segments and having their inner ends pivoted'to each other andtheir outer ends pivoted to said parts, so that upon turning said links radially outward the 'links will be uniii folded and the segments will be moved outwardly and expand the rim for gripping the abrasive band and upon turning the links inwardly the same will be folded and move the segments inwardly to permit the rim to contract and release said band.

3. A polishing wheel comprising a. body having a plurality of segments arranged to form a circular supporting surface on the outer side of the several segments, a hub on which the segments are movably mounted for expanding and contracting the body, an elastic rim mounted on the supporting surfaces of said segments and adapted to carry an abrasive band, and toggles connecting the respective opposing ends of the several segments and each toggle including links extending circumferentially across the space between adjacent parts of the segments and having their inner ends pivoted to each other and their outer ends pivoted to said parts, so that upon turning said links radially outward the links will be unfolded and the segments will be moved outwardly and expand the rim for gripping the abrasive band and upon turning the links inwardly the same will be folded and move the segments inwardly to permit the rim to contract and release said band, said segments being provided adjacent to said links with stop means for arresting the outward movement of said links in their unfolded position.

4. A polishing wheel comprising a body having a plurality of segments arranged to form a circular supporting surface on the outer side of the several segments, a hub on which the segments are movably mounted for expanding and contracting the body, an elastic rim mounted on the supporting surfaces of said segments and adapted to carry an abrasive band, and toggles connecting the respective opposing ends of the several segments and each toggle including links extending circumferentially across the space between adjacent parts of the segments and having their inner ends pivoted to each other, and their outer ends pivoted to said parts, so that upon turning said links radially outward the links will be unfolded and the segments will be moved outwardly and expand the rim for gripping the abrasive band and upon turning the links inwardly the same will be folded and move the segments inwardly to permit the rim to contract and release said band, said segments being provided adjacent to said links with stop means for arresting the outward movement of said links in their unfolded position and the opposing parts of adjacent segments being provided with complementary circumferential tongues and slots which interengage with each other to bridge the space between said segments.

5. A polishing wheel comprising. a body having a plurality of segments which are movable radially relative to the axis of the wheel and each of which is provided with a circumferential bearing flange and a radial web, and a hub including a tube adapted to be mounted on a shaft, a wing projecting laterally from said tube, and a pin and slot connection between said tube and the web of each segment.

6. A polishing wheel comprising a body having a pair of spaced wings projecting laterally from said tube and having their inner parts connected therewith and receiving between the outer parts the webs of said segments, and pin and slot connections between said wings and webs.

7. A polishing wheel comprising a body having a plurality of segments which are movable radially relative to the axis of the wheel and each of which is provided with a circumferential bearing flange and a radial web, and a hub including a tube adapted to be mounted on a shaft, a pair of spaced wings projecting laterally from said tube and having their inner parts connected therewith and receiving between the outer parts the webs of said segments, said wings 8. A polishing wheel comprising a body having a plurality of segments which are movable radially relative to the axis of the wheel and each of which is provided with a circumferential bearing flange and aradial web, and a hub including a tube adapted to be mounted on a shaft, a pair of spaced wings projecting laterally from said tube and having their inner parts connected therewith and receiving between the outer parts the webs of said segments, said wings being provided with slots arranged parallel with a radial line from the axis of the wheel, and pins mounted on said webs and passing through said slots, each of said pins having a central part of relatively large diameter extending through the respective web and reduced necks arranged at opposite ends of said central part and passing PERCIVAL c. MONJAR. 

